“Lethal Leaves” – Part Six

In the last installment of our series on carnivorous plants we consider the “snap trap.” This mechanism is employed by the most famous insectivore plant of all, the Venus Flytrap. The leaf is divided into two lobes with a hinge in the middle. The lobes feature special “trigger hairs” that allow the plant to sense movement, while the edges of the leaves are fringed by stiff thorn-like cilia, which can mesh together to prevent even large prey from escaping.

The Venus Flytrap is so sophisticated that it can differentiate between living prey and a non-living stimulus like a rain drop. A recent study monitored the plant’s electrical responses to stimuli using electrodes. They found that a single touch placed the trap into a ‘ready’ mode. But it took a second stimulation before the trap snapped shut. Then, as the prey struggled to escape, it touched those same trigger hairs multiple times, which electrically excited the plant into sealing the trap and producing its digestive enzymes. The number of ongoing trigger stimuli provided input so that the plant was able to scale the excretion of its specialized digestive cocktail to the size of the prey.

Charles Darwin conducted a number of experiments with the Venus Flytrap, including testing the chemo-sensors with various liquids like milk, alcohol, olive oil, and saliva. He called the plant “one of the most wonderful in the world.” How unfortunate that he neglected to see the great Creator behind the design of the incredible carnivorous plants!